<?
class Config
{
    public static $config = array();

	public static function set($_key, $_val)
	{
        if(!isset(Config::$config[$_key]))
        {
            Config::$config[$_key] = $_val;
        }
        else
        {
           throw new Exception($_key . " 关键字已经存在！");
        }
	}

	public static function get($_key)
	{
        return Config::$config[$_key];
	}
}

?>